1. Field of the Invention
The present invention relates to stationary internal combustion engines and more particularly to a control for stopping the engine in the event of malfunction.
One use of stationary combustion engines has been for operating a water well pump and supplying water pressure to a crop sprinkler system. Since it is impractical for the engine to be attended at all times during its operation some means for stopping the engine is necessary in the event of a malfunction of the engine or other components.
2. Description of the Prior Art
Controls for stopping the operation of a stationary engine are well known, such as an electrical current operated timer or limiting the quantity of fuel available, so that the engine is stopped at a predetermined time. Prior art electrically operated engine controls generally have a drawback, namely, that in the event of a short circuit in the engine control unit the control unit is rendered inoperative and possibly ignites a fire, resulting in considerable damage to the engine. Other proposals for stopping engine operation have been the use of vacuum operated switches interposed in the ignition circuit which interrupts the circuit in the event that the intake manifold vacuum varies from a predetermined value. This type of control similarly has the disadvantage of not responding to engine malfunction, such as loss of water contained by the radiator or failure of an engine driven water well pump.
This invention overcomes the above disadvantages by providing pressure operated valve members connected with a source of air under pressure and the respective component to be monitored so that, in the event of a malfunction of any one component, loss of air pressure normally maintaining a master switch closed opens the switch and interrupts current to the engine ignition.